Waste pipe connector

ABSTRACT

An under-sink waste pipe system comprises first and second waste pipes telescoped together, a softly resilient seal ring that adapts a smaller pipe for coupling to a larger pipe, seals the waste-pipe juncture, and secures the waste pipes together, a locking ring for compressing the sealing ring into resilient locking and sealing engagement with the waste pipes, and a latching mechanism for securing the locking ring in place with the seal ring resiliently compressed a predetermined degree. The latching mechanism maintains the locking ring secured to the end flange structure and comprises at least first and second latching projections on the end flange structure that extend towards the locking ring, and projection guiding cam surfaces formed in the locking ring. Each projection guiding cam surface terminates in a notch-like latching recess. The projection is resiliently urged into the latching recess by the seal ring and snap moves into place to maintain the locking ring latched to the end flange structure and the seal ring resiliently compressed a predetermined degree. The snap-action of the latching mechanism signals the installer that waste pipes are properly coupled.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a continuation-in-part of U.S. patentapplication Ser. No. 09/747,460, filed on Dec. 22, 2000, entitled “WastePipe Connector,” attorney docket no. 15-449C1, which is acontinuation-in-part of U.S. patent application Ser. No. 09/502,738,filed on Feb. 11, 2000, entitled “Waste Pipe Connector,” attorney docketnumber 15-449, which are incorporated herein by reference.

FIELD OF INVENTION

[0002] The present invention relates generally to plumbing connectors.More specifically, the invention is directed to a waste pipe couplingfor securely connecting and sealing telescoped waste pipes.

BACKGROUND OF THE INVENTION

[0003] Conventional residential kitchen sinks typically include afaucet, at least one water receptor basin, and a drain for each basin.Plumbing for directing sink wastewater to a septic system of some sort,or to a sewer, is confined in a small cabinet-like area underneath thesink. The basin drain may be connected to waste pipes in the plumbingdirectly or via a garbage disposer. The garbage disposer grinds largesolids into smaller particulates that pass from the unit and through thewaste pipes. Additionally, the plumbing beneath the residential sink caninclude connections to a dishwasher for carrying dishwasher wastewaterinto the plumbing and to the sewer or septic system.

[0004] The plumbing necessary for removing the wastewater from thebasins, garbage disposer, and dishwasher generally consists ofinterconnected pipes leading to a common waste pipe. In one prior artproposal, interconnected pipes are telescoped together and connected toeach other by means of a screw ring assembly. Prior art screw ringassemblies typically include a screw ring that compresses a relativelyrigid, somewhat pliable, nylon or nylon-like plastic ring against theadjoining pipes to secure them. The plastic ring has a wedge-like, ortriangular, cross sectional shape. The plastic ring has a centralopening that fits around a male pipe end. Plastic pipe rings areavailable with different central opening sizes to accommodate differentmale pipe end sizes. The connection is made by placing the plastic ringand the screw ring around the male pipe end and then telescoping thepipes together. The screw ring is threaded and is screwed onto athreaded end of the female pipe so that the plastic ring is wedged intoengagement with both pipes by the screw ring.

[0005] One problem with these types of connections is that wastewaterflows and operation of the garbage disposer and/or dishwasher causevibrations, shock loadings on the parts, and wrenching forces that, inturn, cause the prior art screw ring assemblies to loosen. The screwring threads do not lock when the screw ring is initially tightened. Theplastic ring is plastically deformed as it is wedged into place. Theseal ring does not accommodate relative movement between the waste pipesthat is created by vibrations in the systems. Moreover, the plasticdeformation of the seal ring results in the seal ring failing tomaintain pressure on the locking ring that creates frictional resistanceto loosening the screw ring. The vibrations cause the screw ring to backaway from the plastic ring along the pipe thread so that seal ringwedging forces are removed. Over time and use, these pipe connectionsare prone to leak. Moreover, the leakage generally worsens over timewith further continued use.

[0006] Another problem with these screw assemblies is that multiple 360°rotations are required to complete assembly of the telescoped pipeconnection. Since the plumbing is generally confined to a small areathat may contain several interconnected pipes, the screw ring assemblyis oftentimes difficult to access. Complete, continuous rotation by awrench is often impeded by the other plumbing fixtures, pipes and undersink structural members. Whether the pipe joint is assembled under asink or not, the installer is often unable to judge how tightly thescrew ring has engaged the plastic ring and wedged it into place.Consequently, in some installations the screw rings were tightened toomuch while in others the screw rings were not tightened enough. When thescrew ring was tightened too much, the plastic ring was over-compressedand distorted by the screw ring. The resulting pipe joint connectionleaked. When the screw ring was too loose, the pipe joint leakedimmediately or in a relatively short time because the parts were notproperly engaged.

[0007] The present invention provides a new and improved under-sinkwaste pipe system that is so constructed and arranged that sealingfailures due to vibrations caused by associated equipment are minimized,leakage resulting from waste pipe seals being compressed too forcefullyor not forcefully enough are completely eliminated, and a tactileindication of proper installation is provided to the waste pipeinstaller.

SUMMARY OF THE INVENTION

[0008] The present invention concerns an under-sink waste pipe couplingfor coupling a first, relatively smaller, waste pipe, and a second,relatively larger, waste pipe telescoped together wherein a softlyresilient seal ring that occupies a space between the waste pipes andseals the juncture of the waste pipes; a locking ring compresses thesealing ring into resilient sealing engagement with the waste pipes;and, a latching mechanism secures the locking ring in place with theseal ring resiliently compressed a predetermined degree.

[0009] The first waste pipe has an end portion defining an outercylindrical surface that extends into the second waste pipe. The secondwaste pipe has an end flange structure surrounding an end opening anddefines a sealing face surrounding the first waste pipe cylindricalsurface when the first waste pipe extends into the end opening. An innersurface of the second waste pipe is substantially spaced apart from theouter cylindrical surface of the first waste pipe.

[0010] The softly resilient seal ring adapts the first, relativelysmaller, pipe for coupling to the second, relatively larger, pipe. Thesoftly resilient seal ring engages the end flange structure sealing faceand extends radially inward to engage the outer cylindrical surface ofthe first waste pipe. The seal ring contacts the first waste pipe outersurface and the end flange sealing face along bands of sealing contact.

[0011] The locking ring is secured to the end flange structure anddefines an opening surrounding the first waste pipe, a forcetransmitting surface surrounding the opening, and a body sectionextending axially from the force transmitting surface. The forcetransmitting surface resiliently deforms the seal ring and urges theseal ring toward resilient engagement with the outer cylindrical surfaceof the end portion and the end flange sealing face. The seal ringsealingly engages the sealing face and sealingly and frictionallyengages the end portion.

[0012] The latching mechanism maintains the locking ring secured to theend flange structure and comprises at least first and second latchingprojections, on one of the locking ring or end flange structure, thatextend towards the other of the locking ring or end flange structure,and projection guiding cam surfaces formed in the other of the lockingring or end flange structure. The projection guiding cam surfaces eachform a notch-like latching recess where the projection is disposed whenthe waste pipes are assembled together. The projection is resilientlyurged into the recess by the seal ring to maintain the locking ringlatched to the end flange structure and the seal ring resilientlycompressed a predetermined degree.

[0013] In a first embodiment of the waste pipe coupling, the forcetransmitting surface of the locking ring engages the seal ring toresiliently deform the seal ring. In a second embodiment of the wastepipe coupling, the force transmitting surface of the locking ringengages a compression flange on the fist pipe to resiliently deform theseal ring.

[0014] The latching recess and cam surface are constructed and relatedso that the projection snap moves into the recess, providing a tactileindication that the pipes are properly assembled together.

[0015] In another embodiment of the invention an under-sink waste pipesystem is provided that comprises first waste pipe having a first endcommunicating with a sewer or septic system, a trap pipe connected tothe first waste pipe, a softly resilient seal ring for sealing the firstwaste pipe to the trap pipe, a locking ring associated with the sealring for resiliently compressing the sealing ring onto sealingengagement with the first waste pipe and the trap pipe, and a latchingmechanism for maintaining each locking ring secured in place with eachsealing ring compressed to a predetermined degree.

[0016] The latching recess and cam surface are constructed and relatedso that the projection snaps into the recess, providing a tactileindication that the pipes are properly assembled together.

[0017] In one embodiment, the seal ring extends into the second wastepipe between the outer cylindrical surface of the first waste pipe andthe inner cylindrical surface of the second waste pipe and the innercylindrical surface of the second waste pipe to stabilize the first andsecond waste pipes. The seal ring may extend through the locking ringopening between the first waste pipe and the locking ring opening tofurther stabilize the coupling.

[0018] Additional features and advantages will become apparent from thefollowing description of an illustrated embodiment made with referenceto the accompanying drawings which form part of the specification andwherein:

BRIEF DESCRIPTION OF THE DRAWINGS

[0019]FIG. 1 is an elevational view of an under-sink waste pipe systemembodying the invention connecting a sink drain pipe and a garbagedisposer to a sewer or septic system;

[0020]FIG. 2 is an exploded view of the waste pipe system of FIG. 1;

[0021]FIG. 3 is a cross sectional view seen approximately from the planeindicated by the line 3-3 of FIG. 1;

[0022]FIG. 4 is a cross sectional view similar to FIG. 3 with partsremoved;

[0023]FIG. 5 is a cross sectional view seen approximately from the planeindicated by the line 5-5 of FIG. 2;

[0024]FIG. 6 is a cross sectional view seen approximately from the planeindicated by the line 6-6 of FIG. 1;

[0025]FIG. 7 is a cross sectional view similar to FIG. 6 with partsremoved;

[0026]FIG. 8 is a cross sectional view similar to the view of FIG. 3showing a coupling of a relatively smaller pipe to a relatively largerpipe; and,

[0027]FIG. 9 is a side elevational view of a seal ring of one embodimentthat adapts a relatively smaller pipe for coupling to a relativelylarger pipe.

DESCRIPTION OF THE BEST MODE CONTEMPLATED FOR THE INVENTION

[0028]FIGS. 1 and 2 illustrate an under-sink waste pipe system 10 fordirecting waste water away from a sink 12 to a sewer, septic system, orthe like, not illustrated. The sink 12 is partially and schematicallyillustrated as comprising first and second basins 14, 16, that areassociated with a water supply, not illustrated, and a garbage disposer18. The basin 14 is fitted with a drain fitting 20 through which thecontents of the basin are drained into the system 10. The basin 16 isfitted with a drain fitting 22 through which the contents of the basin16 are directed to the disposer 18 and then into the system 10.

[0029] The sink 12, i.e. the basins, garbage disposer, and associatedcabinetry, may be of any conventional or suitable construction and istherefore not illustrated in detail. The disposer 18 contains motordriven comminuting blades for pulverizing material that is drained intothe disposer from the basin 16. When the disposer motor is operating thecomminuting blades rotate at high speed and create vibrational forcesthat are transmitted to the waste pipe system 10. When the motor isoperated with one or more relatively large, dense articles inside,sudden, momentary shock forces are generated and transmitted to thewaste pipe system. Moreover, the shock forces may be applied to thecomponents of the waste pipe system as wrenching forces. These forcesall tend to create relative movement between parts of the waste pipesystem 10.

[0030] The system 10 is illustrated as comprising first and second wastepipes 30, 32 communicating with the basin drain 20 and the discharge ofthe garbage disposer unit 18, respectively, a trap pipe 33, a dischargepipe 35 connected to the trap pipe 33 for directing waste from thesystem 10 to a sewer or septic system, a T shaped waste pipe 34 havingbranches 36, 38, 40 connected to the waste pipes 30, 32, and 33, andwaste pipe couplings 42 for detachably connecting the pipes 30, 32, 33and 35 together. The couplings 42 connect the waste pipe junctures in amanner that seals the junctures and maintains the seal integritynotwithstanding vibrations and/or shock loadings transmitted to thesystem 10 from the disposer 18, other elements of the sink, orassociated appliances such as dishwashers.

[0031] The waste pipe 30 has a smooth cylindrical end portion 30 a (FIG.2) that is telescoped into the waste pipe branch 36. The illustratedwaste pipe 30 directs effluent from the basin 14 to the waste pipe 34and has an end portion 30 a having a nominal outside diameter of 1½inches or 1¼ inches and a wall thickness of about 0.068 inches. Theillustrated waste pipe 30 has an end flange (not shown) at its endopposite from the end portion 30 a that is attached to the basin drain20 by a threaded nut-like fastener 43 that serves to clamp a sealinggasket (not shown) between the drain fitting and the waste pipe 30.Although an end flange and fastener 43 are disclosed, the waste pipe 30may be constructed for connection to the basin drain fitting by anysuitable or conventional coupling construction.

[0032] The waste pipe 32 has a smooth cylindrical end portion 32 a (FIG.2) that is telescoped into the waste pipe branch 38. The illustratedwaste pipe 32 directs the effluent from the disposer 18 to the sewer orseptic system via the waste pipe 34. The illustrated waste pipe 32 hasan end portion 32 a having a nominal outside diameter of 1½ inches or 1¼inches and a wall thickness of about 0.068 inches. The illustrated wastepipe 32 has an end flange 32 b at the opposite end from the end portion32 a. The end flange 32 b is shown as attached to the disposer 18 bythreaded fasteners 44 that clamp a sealing gasket (not shown) betweenthe drain fitting and the disposer. Although an end flange 32 b andfasteners 44 are illustrated, the waste pipe 32 may be constructed forconnection to the disposer or other elements of a drain system by anysuitable or conventional coupling construction.

[0033] In the waste pipe 34 of the drawings the branches 36, 38 definebell-like structures 50, 52 at their ends, each forming an end opening53 into which a respective waste pipe 30 or 32 extends. The innerdiameter of each end-bell is slightly larger than the outer diameter ofthe associated waste pipe 30 or 32 so that the pipes telescope togetherrelatively snugly but without appreciable friction. Each end-belldefines a step 54 in the branch inner diameter that limits thetelescoping travel of the waste pipe 30 or 32 into the branch. Theillustrated end-bells have an internal diameter that gradually narrowsproceeding from the end opening 53 to the step 54 so the clearancebetween the waste pipes 30, 34 is greater near the end opening 53 thanat the step 54.

[0034] The illustrated branch 40 has a smooth cylindrical end portion 40a (FIG. 2) that telescopes into the trap waste pipe 33. The illustratedwaste pipe branch end portion 40 a has a nominal outside diameter of 1½inches or 1¼ inches and a wall thickness of about 0.068 inches.

[0035] The trap pipe 33 is formed with a “U” shaped bend 55 that forms atrap for retaining liquid from the sink 12 and sealing the system 10from gases in the sewer or septic system. The trap pipe 33 defines abell-like structure 56 at its first end 33 a that forms an end opening57 into which the waste pipe branch 40 extends. The inner diameter ofthe end-bell is slightly larger than the outer diameter of the branch 40so that the pipes telescope together relatively snugly but withoutappreciable friction. The end-bell 56 defines a step 58 in the trap pipeinner diameter that limits the telescoping travel of the branch 40 intothe trap. The illustrated end-bell has an internal diameter thatgradually narrows proceeding from the end opening 57 to the step 58 sothe clearance between the branch outer diameter and the trap innerdiameter is greater near the end opening 57 than at the step 58.

[0036] The illustrated pipes 30, 32, 33, 34, and 35 are all formed fromhomogenous polypropylene plastic, but they may be formed from anysuitable or conventional materials such as PVC or ABS plastics, brass,or other metals.

[0037] The waste pipe couplings 42 a-42 c secure the waste pipes 30, 32and 33 to the waste pipe 34. The coupling 42 d couples the trap pipe 33to the discharge pipe 35. The illustrated couplings 42 are substantiallythe same so only the coupling 42 a is described in complete detail.Referring to FIG. 3, the coupling 42 a is comprised of the waste pipeend portion 30 a, an end flange structure 62 a surrounding the bellstructure end opening 53 and the end portion 30 a, a seal ring 64 asealingly engaging the end flange 62 a and surrounding and engaging theend portion 30 a, a locking ring 66 a secured to the end flangestructure 62 a and resiliently engaging the seal ring, and a latchingmechanism 70 a for maintaining the locking ring 66 a secured to theflange structure with the seal ring 64 a compressed to a predetermineddegree. The coupling 42 a functions so that the waste pipe 30 isresiliently and frictionally connected to the waste pipe 36 by thecompressed seal ring. The juncture of the waste pipes remains leak freedespite vibrations, shock loads, and wrenching forces that are imposedby the disposer 18 and/or other associated equipment.

[0038] Referring to FIGS. 2 and 3, the end flange structure 62 acomprises an annular flange body 72 a extending about the opening 53 anda sealing face 74 a surrounding the waste pipe end portion 30 a. Theillustrated flange body 72 a is continuous with the waste pipe 34 andextends radially outwardly from the opening 53 and axially along thebranch 36 from the end opening. The illustrated sealing face 74 a isformed by a radially inwardly converging, smooth frustoconical surfaceformed in the end of the flange body 72 a and extending about the endopening 53. The illustrated sealing face has a cone angle of about 45°.The flange body outer diameter is disposed radially outwardly from themajor diameter of the sealing face 74 a while the sealing face minordiameter surrounds the waste pipe end portion 30 a with a smallclearance space.

[0039] The seal ring 64 a is a softly resilient ring that surrounds andresiliently engages the waste pipe end portion 30 a and resilientlyengages the end flange sealing face 74 a. The seal ring 64 a contactsthe waste pipe outer surface and the end flange sealing face 74 a alongbands of sealing contact that are formed by elastic deformation of theseal ring. The resilient engagement force between the seal ring and thepipe end portion 30 a creates a frictional force resisting any tendencyfor vibrational or shock forces to axially separate the waste pipe 30from the branch 36. Further, the resilient engagement between seal ringand pipe assures that the ring and pipe remain engaged even whenvibrations, shocks or other forces are applied that might otherwise tendto create lateral relative movement.

[0040] The illustrated sealing face 74 a is angled relative to the pipe30 so that when the seal ring is compressed axially by the locking ring,the seal ring is urged against the pipe 30 by the sealing face. While afrustoconical sealing face is illustrated, other sealing face shapes maybe employed that function to assure seal ring contact with the pipe 30and sealing engagement with the sealing face.

[0041] The illustrated seal ring 64 a is formed from a nitrile materialhaving a durometer hardness of between 45 and 55 and is softly resilientcompared to the more common standard O-ring that has a durometerhardness of about 70, or higher. A seal ring having a durometer hardnessof between 45 and 55 is selected to ensure that the coupling complieswith ASTM standard F 409-96, Sections 7.3 and 8.3. This ASTM standardrequires that the coupling be able to withstand a fluid pressure of 25psi for one hour without leaking. Testing has shown that sealing ringshaving a durometer hardness greater than 60 do not reliably seal thewaste pipe junctures when the coupling is subjected to the pressure-timeconditions required by the ASTM standard. Among other reasons, theillustrated waste pipes are molded and have side seams that form leakagepaths when seal rings having a durometer hardness greater than 60 aresubjected to conditions required by the standard. Seal rings having adurometer hardness less than 60 are deformed into the side seams andblock leakage. In applications that do not require compliance with ASTMstandard F 409-96, Sections 7.3 and 8.3, the seal ring may have adurometer over about 60. For example, a standard O-ring may be used inthese applications.

[0042] In its relaxed condition, the seal ring 64 a is a torus having anominal inside diameter of about 1.438 in. with the ring body having acircular cross sectional shape that is about 0.103 in. in diameter. Theseal ring internal diameter is slightly smaller than the externaldiameter of the waste pipe end portion 32 a (1½ in.) so that when thering 64 a is placed on the end portion 32 a the cross sectional shape ofthe seal ring is resiliently deformed to a slightly ellipticalconfiguration.

[0043] Although a seal ring for 1½ inch nominal diameter waste pipes hasbeen illustrated and described, a toroidal seal ring having a durometerhardness of less than 60 is also used on a 1¼ inch nominal diameterwaste pipe.

[0044] The locking ring 66 a is secured to the end flange structure 62 aand serves to produce a force for resiliently compressing the seal ring64 a against both the end flange and the waste pipe end portion 30 a.The illustrated locking ring defines an opening 80 a closely surroundingthe end portion 30 a, a force transmitting surface 82 a surrounding theopening 80 a, and a body section 84 a extending axially from the sealring engaging surface toward the end flange structure 62 a. The forcetransmitting surface 82 a is illustrated as a flat annular surfaceformed on a flange-like lip extending radially inwardly from the bodysection 84 a. As illustrated, the force transmitting surface 82 aextends in a direction normal to the longitudinal axis of the waste pipe30. The force transmitting surface 82 a effects resilient deformation ofthe seal ring so that the seal ring is urged toward resilient engagementwith the outer cylindrical surface of the end portion 30 a and thesealing face of the end flange. In the couplings 42 a-42 c the forcetransmitting surface 82 a engages the seal ring while urging the sealring into resilient engagement with the end portion outer cylindricalsurface and the end flange structure sealing face 74 a. The seal ring 64a sealingly engages the sealing face 74 a and sealingly and frictionallyengages the outer surface of the end portion 30 a to maintain the wastepipes assembled. The softly resilient nature of the seal ring 64 aresults in the seal ring making sealing engagement with the end portion30 a, sealing face 74 a, and the force transmitting surface 82 a alongannular bands of contact formed when the seal ring surface is locallyflattened by the contact pressure.

[0045] When assembling the coupling 42 a, the locking ring 66 a isplaced on the waste pipe 30 with the end portion 30 a projecting throughthe opening 80 a. The seal ring 64 a is then assembled over the endportion and the end portion is telescoped into the waste pipe 36. Thelocking ring 66 a is then pressed toward the end flange structure 62 aso that the force transmitting surface 82 a moves the seal ring 64 ainto contact with the flange body seal face 74 a and the locking ringbody section 84 a surrounds the flange body 72 a.

[0046] The locking ring body section 84 a defines an inner peripherythat is disposed about the flange body 72 a when the coupling 42 a isfully assembled. In the illustrated embodiment of the invention,manually grippable ears 86 a project outwardly from the body section 84a. The ears 86 a enable the locking ring 66 a to be gripped and pushedon to the flange body, compressing the seal ring, and then turned tooperate the latching mechanism 70 a. The locking ring body isillustrated as having four ears 86 a.

[0047] The latching mechanism 70 a is constructed and arranged tomaintain the locking ring 66 a secured to the end flange structure 62 awith the seal ring 64 a resiliently compressed to a predetermined degreeagainst the end portion 30 a and the end flange structure 62 a. Theillustrated latching mechanism 70 a comprises latching projections, orlugs, 90 a (FIGS. 2 and 3) on the end flange structure 62 a andprojection guiding cam surfaces 92 a (FIGS. 3-5) formed in the lockingring 66 a. The projections could be formed on the locking ring and thecam surface in the end flange structure. The illustrated projections 90a extend radially outwardly from the flange body outer diameter towardsthe locking ring. In the illustrated coupling the projections are shortcylindrical lugs that are integral, and continuous, with the flangebody. Although the lugs and flange body are illustrated as formed by asingle part, the lugs could be formed by inserts or a separate partattached to the flange body. Four lugs are illustrated, but more orfewer lugs can be provided.

[0048] Each cam surface 92 a engages and guides a respective lug 90 aand coacts with the lug to urge the seal ring 64 a and flange bodytogether. The illustrated cam surfaces are identical so only one isdescribed in detail. The illustrated cam surface forms a side of agroove-like channel 94 a formed in the inner periphery of the lockingring body section 84 a. Each channel 94 a opens in the axial side of thelocking ring body 84 a that confronts the flange body 72 a. The openchannel end has a short axially extending section 96 a that is sized toreceive one of the lugs as the locking ring is pressed axially onto theend flange body. The cam surface 92 a extends along a helical path fromthe axially extending section 96 a so that as the locking ring ismanually rotated, the lug 90 a is constrained to follow the cam surface92 a. The interaction between the cam surface 92 a and the lug 90 aforces the locking ring toward the flange body, compressing the sealring 64 a between the locking ring surface 82 a, the flange body sealingsurface 74 a, and the waste pipe end portion 30 a. The length and helixangle of the cam surface 92 a are selected so that the seal ring 64 a isresiliently compressed beyond the degree of compression that is desiredfor sealing and securing the coupling 42 a. The seal ring 64 a issufficiently softly resilient, and the cam helix angle small enough,that the locking ring 66 a is readily turned by hand during installationof the coupling.

[0049] While a helical cam surface is disclosed, the cam surface couldtake other configurations that would serve to compress the seal ring 64a during assembly of the locking ring to the flange body. Additionally,while the cam surface is illustrated as forming a side of a channel,each cam surface could as well be a side of a land formed on the lockingring body.

[0050] The illustrated latching mechanism 70 a provides a tactileindication that the coupling 42 a is properly installed. The cam surface92 a terminates in a notch-like latching recess 100 that extends axiallytoward the flange body 72 a from the end of the cam face remote from theflange body 72 a. When the lug 90 a reaches the latching recess 100 a,the seal ring urges the lug to the base of the latching recess where thelug is retained by the resilient seal ring force. The lug abruptlyshifts into the latching recess resulting in a tactile snap-action thatserves to signal the coupling installer that the coupling installationis complete. The lug thus over-travels along the cam surface 92 a andover-compresses the seal ring as the locking ring is in the process ofbeing installed. The seal ring relaxes somewhat from its over-compressedcondition as it snap-moves the lug to the base of the latching recess.

[0051] The lug 90 a remains latched in place in the recess 100 a untilthe seal ring is over-compressed again and the locking ring is turned toreturn the lug to the cam surface 92 a. In the meantime, the seal ringremains resiliently compressed in its locking and sealing condition. Thedepth of the recess 100 a predetermines the degree of resilientcompression experienced by the seal ring while the coupling remainsassembled. Further, because the cam surface configuration is fixed bydesign and the latching recess depth is designed to accommodate the sealring 64 a, the seal ring 64 a can not be installed in an over-compressedcondition that could otherwise lead to leakage because of inadequateseal ring resilience. The fact that the seal ring is resilientlycompressed for maintaining the coupling assembled assures that the sealring remains adequately flexible to accommodate vibrational, shock andwrenching forces that may be applied to the coupling by operating thedisposer, etc., without coupling leakage occurring.

[0052] It should be noted that although the coupling 42 c between thetrap pipe 33 and the pipe 34 is identical to the other couplings 42 a,42 b the coupling flange structure is formed on the trap pipe 33 whilethe telescoping pipe end portion is formed on the branch 40.

[0053] The second trap pipe end 33 b is coupled to the discharge pipe 35(also referred to as a wall arm) by the coupling 42 d. The trap pipe 33defines a second bell-like structure 56 a at its end 33 b that forms anend opening 57 d into which the discharge pipe 35 extends. The innerdiameter of the end-bell is slightly larger than the outer diameter ofthe discharge pipe 35, so that the pipes telescope together relativelysnugly but without appreciable friction. The illustrated end-bell has aninternal diameter that gradually narrows proceeding from the end opening57 d to the step 58 dso the clearance between the branch outer diameterand the trap inner diameter is greater near the end opening 57 d than atthe step 58 d.

[0054] The illustrated discharge pipe 35 has an end portion 35 a thattelescopes into the trap pipe 33 (FIG. 6). The illustrated dischargepipe end portion 35 a has a nominal outside diameter of 1½ inches or 1¼inches and a wall thickness of about 0.068 inches.

[0055] The coupling 42 d is constructed slightly differently from thecouplings 42 a-42 c and is illustrated in FIGS. 2 and 6. The coupling 42d is comprised of the discharge pipe end portion 35 a, an end flangestructure 62 d surrounding the bell structure end opening 57 d and theend portion 35 a, a seal ring 64 d sealingly engaging the end flange 62d and surrounding and engaging the end portion 35 a, a locking ring 66 dsecured to the end flange structure 62 d and the compression flange 61,and a latching mechanism 70 d for maintaining the locking ring securedto the flange structure with the seal ring 64 d compressed to apredetermined degree. The coupling 42 d functions so that the dischargepipe 35 is resiliently and frictionally connected to the trap pipe 33.The juncture between the trap pipe 33 and the discharge pipe 35 remainsleak free despite vibrations, shock loads, and wrenching forces that areimposed by the disposer 18 and/or other associated equipment.

[0056] The locking ring 66 d is the same as the locking rings 66 a-66 c.The coupling 42 d differs from couplings 42 a-42 c in that it comprisesa compression flange 61 for transmitting compressive force from thelocking ring to the seal ring and the latching mechanism lugs 90 d arepositioned differently to accommodate the thickness of the compressionflange 61. As illustrated in to FIGS. 2, 6, and 7, the compressionflange 61 comprises an annular flange body extending about thecylindrical surface 63 of the discharge pipe 35. The illustratedcompression flange is continuous with the discharge pipe 35 and extendsradially from the cylindrical surface 63 with its opposite facesdisposed in planes that are normal to the axis of the pipe 35. The pipeend portion 35 a performs a piloting function and supports the seal ringin position during assembly of the coupling 42 d. The compression flange61 forms a stop that limits movement of the seal ring away from theflange 62 d during assembly as well as limiting travel of the pipe endportion 35 a into the end bell.

[0057] The force transmitting surface 82 d of the locking ring 66 dcontacts the compression flange 61 and transmits compressive forcethrough the compression flange 61 to the seal ring 64 d. The seal ringis thus urged into sealing engagement with the end flange 62 d, the pipeend portion 35 a and the compression flange 61. The lugs are formedcontiguous with the planar end flange 91 so that the locking ring 66 dcan accept the lugs into the channels 94 d with both the compressionflange 61 and seal ring 64 d contained between the force transmittingsurface 82 d and the end flange 62 d. In the illustrated coupling thelugs are cylindrical and located tangent to the plane of the face 91.The compression flange 61 is locked between the locking ring 66 d andthe end flange structure 62 d to prevent removal of the discharge pipefrom the trap pipe 33, while enabling the seal ring to resilientlycushion axial shocks applied to the coupling.

[0058] FIGS. 8 illustrates a coupling 200 that uses an alternate sealring 210 that adapts a relatively smaller inner pipe 212 for coupling toa relatively larger outer pipe 214. In the embodiment illustrated byFIG. 8, the end flange structure 62 a surrounding the bell structure endopening 53, the locking ring 66 a secured to the end flange structure 62a, and the latching mechanism 70 a for maintaining the locking ring 66 asecured to the end flange structure are substantially the same as theones used in coupling 42 a, illustrated by FIG. 3. An end portion 226 ofthe smaller pipe 212 is similar to the end portion 30 a, but has asmaller diameter in the illustrated embodiment. An outer cylindricalsurface 216 of the smaller pipe 212 is substantially spaced apart froman inner cylindrical surface 218 of the larger pipe 214. The seal ring210 includes a softly resilient annular sealing portion 220. The annularsealing portion 220 includes an inner surface 224 (FIG. 8) thatsurrounds and engages the outer cylindrical surface 216 of the endportion 226 of the smaller pipe 212 along a band of sealing contacts.The sealing portion 220 extends radially outward past the innercylindrical surface 218 of the larger pipe 214 to a sealing faceengaging surface 228. The sealing face engaging surface 228 engages asealing face 74 a of the end flange structure 62 a along a band ofsealing contacts.

[0059] In one embodiment, the seal ring 210 includes an annular pipestabilizing portion 222, extending axially from the sealing portion 220.The annular pipe stabilizing portion 222 extends into the larger pipe214 and occupies a space 230 between the outer cylindrical surface 216and the inner cylindrical surface 218. The pipe stabilizing portioninhibits axial and radial movement of the smaller pipe with respect tothe larger pipe, resulting in a more secure coupling.

[0060] In the illustrated embodiment, the sealing face engaging surface228 of the sealing portion 220 is formed by a radially inwardlyconverging, smooth frusto-conical surface that corresponds to thesealing face 74 a. The illustrated sealing face engaging surface 228 hasa cone angle of about 45°.

[0061] In the embodiment, illustrated by FIGS. 8 and 9, the sealingportion 220 includes a planar engagement surface 232. In thisembodiment, the force transmitting surface 82 a of the locking ringengages the engagement surface 232 to effect resilient deformation ofthe sealing portion 220 so that the sealing portion is urged towardresilient engagement with the outer cylindrical surface 218 of thesmaller pipe 212 and the sealing face 74 a of the end flange.

[0062] The pipe stabilizing portion 222 is cylindrical and extendsaxially from the sealing portion 220. The illustrated stabilizingportion 222 resiliently engages the inner cylindrical surface of thelarger pipe 214 and the outer cylindrical surface 216 of the smallerpipe to stabilize the coupling 200.

[0063] In the embodiment illustrated by FIGS. 8 and 9, the seal ring 210includes a locking ring stabilizing portion 236. The locking ringstabilizing portion end extends axially from the sealing portion 220.The locking ring stabilizing portion extends through the locking ringopening 80 a and occupies a space between the locking ring opening 80 aand the smaller pipe 212 to further stabilize the coupling.

[0064] The seal ring 210 is made from a softly resilient material. Theseal ring 210 surrounds and engages the end portion 226 to effectivelyincrease the diameter of the smaller pipe 212. The sealing portion 220of the seal ring 210 resiliently engages the end flange sealing face 74a. The seal ring 210 contacts the outer surface 216 and end flangesealing face 74 a along bands of sealing contacts that are formed byelastic deformation of the sealing portion 220 of the seal ring 210. Theresilient engagement force between the seal ring and the pipe endportion 226 creates a frictional force resisting any tendency forvibrational or shock forces to axially separate the smaller pipe 212from the larger pipe 214.

[0065] The locking ring 66 a is secured to the end flange structure 62 aand serves to produce a force for resiliently compressing the sealingportion 220 against both the end flange and the smaller pipe outercylindrical surface 216. In the embodiment illustrated in FIG. 8, theopening 80 a surrounds the locking ring stabilizing portion 236 of theseal ring 216. The force transmitting surface 82 a effects resilientdeformation of the sealing portion 220 so that the sealing portion isurged toward resilient engagement with the outer cylindrical surface 216of the smaller pipe and the sealing face of the end flange. The sealring 210 sealingly engages the sealing face 74 a and sealingly andfrictionally engages the outer surface 216 of the smaller pipe 212 tomaintain the pipes assembled. The softly resilient nature of the sealring 210 results in the seal ring making sealing engagement with theouter surface 216 and sealing face 74 a.

[0066] When assembling the coupling 200, the locking ring 66 a is placedon the smaller pipe 212 with the end portion 226 projecting through theopening 80 a. The seal ring 210 is then assembled over the end portion.The end portion 226 and pipe stabilizing portion 222 are telescoped intothe larger pipe 214. The locking ring 66 a is then pressed toward theend flange structure 62 a so that the force transmitting surface 82 amoves the sealing portion 220 into contact with the end flange seal face74 a and the locking ring body section 84 a surrounds the flange body 72a.

[0067] The latching mechanism 70 a is constructed and arranged tomaintain the locking ring 66 a secured to the end flange structure 62 awith the sealing portion 220 compressed to a predetermined degreeagainst the outer surface 216 and the end flange structure 62 a. Thelatching mechanism resiliently compresses the sealing portion 220 beyondthe degree of compression that is desired for sealing and securing thecoupling 200. When the lug 90 a reaches the latching recess 100 a, thesealing portion 220 urges the lug to the base of the latching recesswhere the lug is retained by resilient seal ring force. The lug abruptlyshifts into the latching recess resulting in a tactile snap-action thatserves to signal the coupling installer that coupling installation iscomplete. The lug thus over-travels along the cam surface 92 a andover-compresses the sealing portion 220 as the locking ring is in theprocess of being installed. The sealing portion relaxes somewhat fromits over-compressed condition as it snap-moves the lug to the base ofthe latching recess. The seal ring 210 is sufficiently softly resilient,and the cam helix angle small enough, that the locking ring 66 a isreadily turned by hand during installation of the coupling.

[0068] The lug 90 a remains latched in place in the recess 100 a untilthe seal ring is over-compressed again and the locking ring is turned toreturn the lug to the cam surface 92 a. In the meantime, the sealingportion 220 remains resiliently compressed in its locking and sealingcondition. The depth of the recess 100 a predetermines the degree ofresilient compression experienced by the sealing portion 220 while thecoupling remains assembled. The latching mechanism 70 a does not allowthe sealing portion 220 to be installed in an over-compressed condition.The resiliently compressed sealing portion accommodates vibrational,shock and wrenching forces that may be applied to the coupling.

[0069] The seal ring 210 illustrated in FIG. 9 could be used in one ormore of the couplings 42 a-42 c to accommodate a smaller inner pipe.

[0070] In one embodiment, the locking ring stabilizing portion 236 isomitted from the seal ring 210. In this embodiment, the seal ring 210can be used in the coupling 42 d to accommodate a smaller pipe having acompression flange 61. In this embodiment, the compression flange 61engages the sealing portion 220 to bring the sealing portion intoengagement with the end flange sealing face and the outer cylindricalsurface of the smaller pipe.

[0071] While the invention has been illustrated and described inconsiderable detail, the invention is not to be considered limited tothe precise construction disclosed. Various adaptations, modifications,and uses of the invention may occur to those skilled in the art to whichthe invention pertains. The intention is to cover all such adaptations,modifications, and uses that fall within the spirit or scope of theappended claims.

We claim:
 1. In an under-sink waste pipe system having first and secondwaste pipes connected together for carrying wastewater away from abasin, a waste pipe coupling comprising: a) a first waste pipe endportion defining an outer cylindrical surface of said first waste pipe;b) a second waste pipe end portion defining an inner cylindrical surfaceof said second waste pipe; c) an end flange structure of said secondwaste pipe surrounding an end opening, said outer cylindrical surface ofsaid first waste pipe extending into said end opening, said first wastepipe outer cylindrical surface being substantially spaced apart fromsaid second waste pipe inner cylindrical surface, said end flangestructure defining a sealing face surrounding said first waste pipeouter cylindrical surface when said first waste pipe extends into saidend opening; d) a softly resilient seal ring engaging said end flangesealing face and extending radially inward past said inner cylindricalsurface to engage said outer cylindrical surface of said first wastepipe, said seal ring contacting said first waste pipe outer surface andsaid end flange sealing face along bands of sealing contact; e) alocking ring secured to said end flange structure, said locking ringdefining an opening surrounding said first waste pipe, a forcetransmitting surface surrounding said opening, and a body sectionextending axially from said force transmitting surface toward said endflange structure, said force transmitting surface effecting resilientdeformation of said seal ring so that said seal ring is urged towardresilient engagement with the outer cylindrical surface of said endportion and said sealing face of said end flange structure, said sealring sealingly engaging said sealing face and sealingly engaging saidend portion; and, f) a latching mechanism maintaining said locking ringsecured to said end flange structure, said latching mechanism comprisingat least first and second latching projections on one of said lockingring or end flange structure, each projection extending towards saidother of said locking ring or end flange structure, and projectionguiding cam surfaces formed in said other of said locking ring or endflange structure, each projection guiding cam surface terminating in anotch-like latching recess where said projection is disposed when saidwaste pipes are assembled together, said projection resiliently urgedinto said latching recess by said seal ring to maintain said lockingring latched to said end flange structure and said seal ring resilientlycompressed a predetermined degree.
 2. The coupling of claim 1 whereinsaid force transmitting surface engages said seal ring to resilientlydeform said seal ring.
 3. The coupling of claim 1 wherein said couplingfurther comprises a compression flange on said first waste pipeinterposed between said force transmitting surface and said seal ring,said force transmitting surface engaging said compression flange on saidfirst pipe to resiliently deform said seal ring.
 4. The coupling claimedin claim 1 wherein said seal ring extends into said second waste pipebetween said outer cylindrical surface of said first waste pipe and saidinner cylindrical surface of said second waste pipe.
 5. The couplingclaimed in claim 1 wherein said seal ring extends through said lockingring opening between said locking ring opening and said first wastepipe.
 6. The coupling claimed in claim 1 wherein said seal ring has aslightly smaller inside diameter than the outside diameter of the firstwaste pipe.
 7. The coupling claimed in claim 1 wherein said end flangesealing face is conical and converges toward said first waste pipe in adirection proceeding away from said locking ring.
 8. The couplingclaimed in claim 1 wherein said latching projections are formed on saidend flange structure and extend radially outwardly therefrom and saidprojection guiding cam surfaces are formed on said locking ring.
 9. Thecoupling claimed in claim 1 wherein said locking projection guiding camsurfaces are formed on the locking ring body confronting the end flangestructure, said cam surfaces defining a ramp section extending to saidlatching recess, said ramp section assuring that said sealing ring isresiliently compressed to a greater extent than said predetermineddegree before said projections enter said latching recess.
 10. Thecoupling of claim 1 wherein said end flange includes a planar end face,said-latching projections are cylindrical lugs that are tangent to saidplanar end face.
 11. The coupling of claim 1 wherein the outercylindrical surface of said first waste pipe is approximately 1.25inches in diameter and the inner cylindrical surface of said secondwaste pipe is approximately 1.5 inches in diameter.
 12. In an under-sinkwaste pipe system comprising: a) a first waste pipe having a first endportion in communication with a sewer or septic system and a second endportion defining an outer cylindrical surface; b) a trap pipe having anend flange structure surrounding an end opening and an inner cylindricalsurface, said outer cylindrical surface of said first waste pipeextending into said end opening, said outer cylindrical surface beingsubstantially spaced apart from said inner cylindrical surface, said endflange structure defining a sealing face surrounding said first wastepipe outer cylindrical surface when said first waste pipe extends intosaid end opening; c) a softly resilient seal ring engaging said endflange structure sealing face and extending radially inward past saidinner cylindrical surface to engage said outer cylindrical surface ofsaid first pipe, said seal ring contacting said first waste pipe outersurface and said end flange sealing face along bands of sealing contact;d) a locking ring secured to said end flange structure, said lockingring defining an opening surrounding said first waste pipe, a forcetransmitting surface surrounding said opening and a body sectionextending axially from said force transmitting surface, said forcetransmitting surface effecting resilient deformation of said seal ringfor urging said seal ring toward resilient engagement with the outercylindrical surface of said second end portion and said sealing face ofsaid end flange structure, said seal ring sealingly engaging saidsealing face and sealingly engaging said second end portion; and, e) alatching mechanism maintaining said locking ring secured to said endflange structure, said latching mechanism comprising at least first andsecond latching projections on one of said locking ring or end flangestructure, each projection extending towards said other of said lockingring or end flange structure, and projection guiding cam surfaces formedin said other of said locking ring or end flange structure, eachprojection guiding cam surfaces terminating in a notch-like latchingrecess where said projection is disposed when said waste pipes areassembled together, said projection resiliently urged into said latchingrecess by said seal ring to maintain said locking ring latched to saidend flange structure and said seal ring resiliently compressed apredetermined degree.
 13. The waste-pipe system claimed in claim 12wherein said force transmitting surface engages said seal ring toresiliently deform said seal ring.
 14. The coupling claimed in claim 12wherein said seal ring extends into said second waste pipe between saidouter cylindrical surface of said first waste pipe and said innercylindrical surface of said second waste pipe.
 15. The coupling claimedin claim 12 wherein said seal ring extends through said locking ringopening between said locking ring opening and said first waste pipe. 16.The system claimed in claim 12 wherein each of said end flange sealingfaces is conical and converges toward said first waste pipe in adirection proceeding away from said locking ring.
 17. The system claimedin claim 12 wherein said latching projections are formed on said endflange structure and extend radially outwardly therefrom and saidprojection guiding cam surfaces are formed on said locking ring.
 18. Thesystem claimed in claim 12 wherein said locking projection guiding camsurfaces are formed on said locking ring body confronting the associatedend flange structure, said cam surfaces defining a ramp sectionextending to said latching recess, said ramp sections assuring that saidsealing ring is resiliently compressed to a greater extent than saidpredetermined degree before said projections enter said latchingrecesses.
 19. The coupling of claim 12 wherein the outer cylindricalsurface of said first waste pipe is approximately 1.25 inches indiameter and the inner cylindrical surface of said trap pipe isapproximately 1.5 inches in diameter.
 20. In an under-sink waste pipesystem that includes first and second waste pipes and a locking ring,wherein an outer cylindrical surface of the first waste pipe issubstantially spaced apart from an inner cylindrical surface of thesecond waste pipe, the second waste pipe defines an end flange structurethat defines a sealing face surrounding the first waste pipe, and thelocking ring includes an opening that surrounds the first waste pipe andis secured to the end flange structure of the second waste pipe, a sealring that adapts a relatively smaller first pipe for coupling to arelatively larger second pipe, comprising: a) a softly resilient annularsealing portion that includes an inner surface that surrounds andengages the first waste pipe end portion along a band of sealingcontact, said seal ring extending radially outward from said innersurface past the inner surface of the second waste pipe to a sealingface engaging surface that engages the end flange structure sealing facealong a band of sealing contact; and, b) an annular pipe stabilizingportion extending axially from said sealing portion into said secondwaste pipe, said pipe stabilizing portion occupies a space between saidouter cylindrical surface of said first waste pipe and said innercylindrical surface of said second waste pipe.
 21. The adapter of claim20 further comprising a locking ring stabilizing portion extendingaxially from said sealing portion through said locking ring opening,said locking ring stabilizing portion occupies a space between saidlocking ring opening and said first waste pipe.